Center locating and scribing device



March 20, 1962 D. HENDRIX 3,025,609

CENTER LOCATING AND SCRIBING DEVICE Filed Dec. 12, 1960 2 Sheets-Sheet lINVENTOR. DEWEY HENDRIX BY MAMM W ATTORNEYS.

March 20, 1962 D. HENDRIX 3,025,609

CENTER LOCATING AND SCRIBING DEVICE Filed Dec. 12, 1960 2 Sheets-Sheet 2INVENTOR. D EW EY HENDRD ATTORNEYS United States Patent CENTER LGCATINGAND SQRIEING DEVICE Dewey Hendrix, ISM-A Salem Road, Morganton, NC.Filed Dec. 12, 1960, Ser. No. 75,169 4 Claims. (Cl. 33-491) Thisinvention relates to center locating devices and, more particularly, toan improved center locating device of the type customarily having acentral hub and a plurality of radial arms mounted in the same orparallel planes for simultaneous coextensive longitudinal movementthrough the hub. One well known device of this type customarily employstwo pairs of arms mounted for movement through the hub, the arms of eachpair extending parallel to one another, but perpendicular to the arms ofthe other pair.

Centering devices of the type described generally above have found wideapplication in accurately locating the centers of objects having across-sectional shape which is either circular, or of other regularpolygonal configuration in which the number of sides of the polygon is amultiple of four. Inherent in the heretofore known devices, however, isa lack of versatility which impairs, if not obviates, their utility forquickly and accurately locating the centers of objects having across-sectional shape other than as described above; e.g., an objectwhich is irregularly polygonal, or hexagonal, in cross-section.

It is, accordingly, a primary object of this invention to provide adevice of the type described which has an enhanced versatility,particularly in that it may be used to more quickly and accuratelylocate desired points upon various regularly polygonal work surfaceswhich are neither circular or have a number of sides which is a multipleof four.

Another object of this invention is the provision of a device capable ofutilization upon cross-sectional shapes of irregular polygonalconfiguration and which have a single pair of elongated parallel sides,and more particularly which is capable of locating the center and otherlines parallel to such sides.

Still another primary object is to provide a novel device of economical,compact, and durable construction which is capable of locating both thecenter of a work surface and, additionally, various desired radialpoints from such center. This is particularly beneficial, for instance,when working with a flanged object in which it is desired to locate bothan axial bore and various radial bolt holes.

A more specific object is the provision upon the outer end of one ormore arms of a device of the type described of a work engaging jaw orfoot which is movably mounted so that it can be optionally placed inwork engaging position or readily moved to an inactive location; and inwhich one or more radial-point locating members is slidably mounted uponan arm or arms of the device.

Still other objects and advantages of the invention will be in partevident and in part pointed out hereinafter in the following descriptionof an illustrative embodiment of the invention, which should be read inconjunction with the accompanying drawings, in which- FIGURE 1 is a topperspective view of a device according to the invention suspended abovea circular work surface, two feet of the device being shown in alocation to engage work and the remaining two feet being shown in aninactive location;

FIGURE 2 is a plan view, in reduced scale, of the device in centerlocating position upon the work surface shown in FIGURE 1, all of thefeet of the device being shown in work engaging location;

FIGURE 3 is a side elevation of the device;

FIGURE 4 is an enlarged horizontal section taken 3,Z5,bll9 Patented Mar.26, I952 along line 44 of FIGURE 3 of the hub structure of the device;

FIGURE 5 is an enlarged horizontal section taken along line 5-5 ofFIGURE 3 of the hub structure of the device;

FIGURE 6 is an enlarged horizontal section taken along line 66 of FIGURE3 of the hub structure of the device;

FIGURE 7 is an enlarged vertical section taken approximately along line7-7 of FIGURE 2 of the hub structure of the device;

FIGURE 8 is a horizontal section taken along line 38 of FIGURE 7 of theoperating knob and punch of the device;

FIGURE 9 is a plan view of the device positioned upon a work surface ofirregular polygonal configuration; and

FIGURE 10 is a plan view of the device positioned upon a work surface ofhexagonal configuration.

Referring more particularly to the drawings, a device according to theinstant invention is identified in its entirety in FIGURE 1 by thenumeral 12, and includes generally a central hub 14 having two pairs ofarms 18, 2t] and 22, 24 radiating outwardly therefrom in parallelplanes, the arms 18, 2t and 22, 24 of each pair being parallel to oneanother and perpendicular to the arms of the other pair, and all of thearms being mounted in a manner described more fully hereinafter forsimultaneous coextensive longitudinal movement through hub 14. While forpurposes of illustration, the instant invention is disclosed as appliedto and in conjunction with the well known structure thus far described,no restriction thereto is intended, for it will become apparent thatother type structurese.g., those having a greater or lesser number ofradial armsmight also employ the various novel teachings hereinafterdiscussed.

Referring now once again to the drawings, particularly FIGURES 3 through7, it will be seen that hub 14 comprises a pair of square plates 26, 28,each of which is provided with a pair of spaced parallel slots orchannels 30 connected by a recessed central portion 31, a central bore32, and a notch 33 midway of each edge; the plates being securedtogether by screws 34 (see FIGURE 1) with the channels 3% of eachextending normal to channels 34 of the other and with portions 381,bores 32 and notches 33 in alignment. The outer face of one of theplates, illustratively that of plate 28, constitutes the base 35 of thehub 14 thus formed.

Slidably mounted in channels 30 parallel to and above base 35 of hub 14are arms 18, 2t), 22, 24, the inner face of each of which is providedwith notches or teeth 36. In order to impart simultaneous coextensivelongitudinal movement to the arms, a single driving mechanism inengagement with the teeth 36 of each arm is provided within hub 14. Thismechanism includes a sleeve or spindle 38 rotatably mounted withinaligned bores 32 of hub 14 and projecting above at its upper end beyondsaid bores. The lower inner end of spindle 38 mounts a pinion or gear 39received within sunken portions 31 of hub 14 and of sufficient diameterand height to engagethe teeth 36 of each arm, and the projecting upperend of the spindle is contained within the axial bore 44} of anoperating knob 42 located upon the upper surface of hub I4. It will benoted from FIGURE 7 that knob 42 is provided with a hollow interiorportion or cavity 43, the purpose of which will be discussedhereinafter. Both gear 39 and knob 42 are rigidly secured to spindle 38by any suitable means; illustratively, gear 39 may be pressed thereon,and knob 42 may be secured by means of set screws 44, as shown. It isapparent that with the construction described, rotation of knob 4-2 willsimultaneously impart rotation to gear 39 and thereby cause the arms 18,20, 22, 24 to a move coextensively in unison in the direction of thelongitudinal axis of each.

In order to lock the radial arms in any desired longitudinal position,an annular member 46 is secured atop hub 14, as by means of screws 48,with its inner surface in bearing contact with the outer shaft surfaceof knob 42. Member 46 is provided with a radial bore 4'7 (see FIGURE 6)to permit access to set screws 44, and with a threaded outer surfacewhich is engaged by the complementary inner threaded surface of lockingring 54, as best shown in FIGURE 7. Beneath the lower surface of locking ring 54 are the upper ends of a plurality of pin members 58, 6t 62,64 which are mounted for vertical reciprocation within bores 66 providedtherefor in plate 26 of hub 14. The lower ends of pins 58, 60 rest uponarms 18, 20, respectively, and the lower ends of pins 62, 64 rest uponarms 22, 24. The length of pins 58, 6t? is somewhat greater than thelength of pins 62, 64 so that the upper ends of all the pins lie withinthe same plane,

which is within the path of vertical movement of ring 54. Thus, whenlocking ring 54 is rotated in a direction to move it downwardly, thelower surface thereof will abut the upper ends of the pins and urge thelower ends downwardly against the. arms they contact, simultaneouslylocking all of the arms against movement. When locking ring 54 isrotated in the opposite direction and thus moved upwardly out of contactwith pins 58, 6t 62, 64, the lower ends of these numbers will merelyrest upon their respective arms, and exert no locking forcethereagainst.

It is contemplated that the desired rotative movement of both knob 42and locking ring 54 will be achieved manually, and to assist in thisregard the outer surfaces of both of these members may be knurled orotherwise suitably roughened, as indicated at 74.

As noted heretofore, knob 42 is provided with a hollow interior orcavity 43, and also with an axial bore 40. Extending through bore 46 andslidably mounted within spindle 38 is a punch 82 having an annulargroove 89. Cavity 43 in knob 42 accommodates the two halves of a leafspring 78, best seen in FIGURES 7 and 8, which engage groove 80 and thusresiliently maintain punch 82 in a normally upward position with theupper end thereof projecting above knob 42 and the lower end enclosedwithin spindle 38, as shown. It will be apparent that when in itsnormally upward position, punch 82 will not project beyond the lowersurface of hub 14 or otherwise interfere with the positioning of device12 upon a work surface. When the center of the work has been located,however, in a manner described more fully hereinafter, the punch mayreadily be depressed as by means of a hammer blow upon its projectingupper end, so that its lower end will strike the work surface andpermanently record the location of the center.

Referring now particularly to FIGURE 1, upon the outer end of eachradial arm of device 12 there is rigidly secured, as by means of rivets86, a bracket 84 having a vertical planar face 35. Extending outwardlyfrom face 85 of each bracket 84 are a plurality of pins 88, 9d, 92, andmounted upon each pin 92 for pivotal movement in a vertical direction(as indicated by the two-headed arrows in FIGURE 1) is a foot member 94of generally L-shaped configuration. Pins 8%, 90, serve to bothdelineate the opposite extreme pivotal locations of each foot 94, and tomaintain each foot in one or the other of such locations. Thus, each pin9th defines the extreme downward pivotal location of a foot 94, in whichposition the foot is properly situated to engage the work, with itsmajor leg 95 being disposed beneath the plane of base of hub 14- andextending radially inwardly as illustrated by the feet upon arms 18, 2%in FIGURE 1. The length of the major leg 95 of each foot 94 is such thatwhen positioned as described the inner end thereof will be adjacent bore32 when the arms of the device are fully retracted,

which permits utilization of the device upon work of extremely smalldiameter. When it is desired to move a foot 94 to an inactive, non-workengaging location above the plane of base 35, this may be quickly andeasily accomplished merely by manually pivoting the same upwardly aboutpin 92 until it engages and rests upon its pin 88, as illustrated by thefeet upon arms 22, 24 in FIGURE 1, and as shown in FIGURE 3. It will benoted that when a foot 94 is in this upward position, it is disposedentirely above the plane of base 35 of hub 14 and extends radiallyoutwardly, as shown. The provision of foot members which may be quicklymoved from an active, work engaging location to an inactive, non-workengaging location-and vice versa-is deemed to be a highly significantand novel feature of the instant device, which contributes markedly toits enhanced versatility as will be noted in the susequent discussionherein of the operation of the device.

Another highly significant and related feature is the provision of meansfor ascertaining upon a work surface the location of various points and/or lines radially spaced from the center of hub 14. This may beaccomplished by locating blocks 96 which, as best seen in FIGURES 1 and3, are each provided with an opening 98 extending horizontallytherethrough for reception of and slidable mounting upon an arm of thedevice, and a vertical bore 1% through a projecting portion 101 thereof.When the blocks 96 are mounted upon the arms of the device, as shown,they are disposed entirely above the plane of base 35 of hub 14 and theprojected axis of the bore 10E} of each will intersect a radius betweena foot 94 and the axis of punch 82. Therefore, when device 12 iscentered upon a work surface, a desired radius may be drawn by thesimple expedient of insert-' ing a stylus or the like in the bore ltltlof any block 96, and by sliding that block along its arm between bracket84 and the inner face of notch 33 while maintaining the stylus incontact with the work surface. In order that the location of variouspoints upon such radius might be determined if desired, the arms 18, 20,22, 24 may be provided along their lengths, preferably upon their uppersurfaces, with identical indicia of measure 163 properly correlated tothe shape of the block so that the linear distance of the axis of eachbore from punch 82 can be quickly ascertained. Additionally, it ispreferred that each block 96 be provided with a locking screw 102extending therethrough and bearing upon the arm received within itsopening 98, so that each block can be quickly locked in place orreleased for sliding movement merely by rotation in the appropriatedirection of its screw 102. To facilitate the manual rotation of screws102, the outer surface of each may be knurled as at 74, if desired.

Having now described in detail the structure of a device according tothe instant invention, a few illustrative modes of operation andadvantages thereof will be noted. When the device is employed to findthe center of an object having a cross-section shape which is circular,or of other regular polygonal configuration in which the number of sidesof the polygon is a multiple of four, each foot 94 is positioned in itslower location abutting stop-pin 90, the device is placed with base 35of hub 14- resting upon the work, and the arms 18, 20, 22, 24simultaneously and coextensively moved by rotating knob 42 until theinner end of each foot 94 engages the edge of the work. Punch 82 willthen be situated over the center of the work, and such center may bemarked by striking the upper end of punch 82 with a hammer or the like.

A more detailed explanation of the operation of the device in thuslocating the center of work of circular or other cross-sectioned shapenoted above is not deemed necessary, since such operation is materiallythe same as that of various rigid foot devices heretofore known and nowin general usage. Discussion may therefore be now directed to otherfunctions which a device embodying the invention is capable ofperforming, and to its mode of operation in conjunction with work havinga cross-sectional shape other than as noted above.

Thus by reference to FIGURES 1 and 2, it will be apparent that once thedevice 12 is centered upon work of circular cross-section, for instancethe work 106 shown, the location of any desired radial point may beeasily determined; an illustrative instance when this capability isextremely desirable, as noted heretofore, is when seeking to locate bothan axial bore and various radial bolt holes in a flanged object. Inlocating the desired radial points, preferably locking ring 54 is firstrotated in a direction to bear against pins 58, 6t], 62, 64 and therebysimultaneously secure arms 18, 20, 22, 24 against accidentaldisplacement. Blocks 96 may then be moved a predetermined distancewhichmay, but need not necessarily be the same for each-along theirrespective arms, as indicated by indicia 103, a stylus or the likeinserted within the bores 100, and the point or points marked upon thework surface. If desired, any or all of blocks 96 can then be locked totheir arms by means of screws 102, and device 12 rotated bodily in theplane of the work so as to determine another set of points located thesame radial distance, but circumferentially spaced, from the former. Itwill also be noted that by holding a stylus within a bore 1% whilebodily rotating the device 12, any number of circles concentric with theouter edge of work 106 might be inscribed.

The utility of the device with respect to work surfaces which areirregularly polygonal, or regularly polygonal, but having a number ofsides not a multiple of four, is illustrated in FIGURES 9 and 10,respectively, to which reference is now made.

In FIGURE 9, device 12 is shown properly siutated upon work 1% having asingle pair of parallel sides, but of irregular polygonal cross-section,such as a plank, beam, or the like. Two of the feet 94-illustrativelythose upon arms 13, 2-8are in their upward non-work engaging position,thus permitting base 35 of hub 14 to rest upon work 188 and the othertwo feet 94, which are in their downward position upon arms 22, 24, toengage opposite parallel edges. When thus situated, a center line may beinscribed along the entire length of work 108 by locking the armsagainst movement (if desired), holding punch 32 in depressed conditionor inserting a stylus in the block 96 upon either arm 18 or 20, andsliding the device 12 longitudinally of the work. Additionally, byutilizing blocks 96 upon arms 22, 24 in the manner previously described,any number of lines K parallel to and a predetermined distance from suchcenter line and the parallel edges of work 1% might be inscribed.

It should be apparent that a device having work engaging feet notreadily movable into an inactive location could not be utilized in themanner shown in FIGURE 9, since those feet upon the arms extendinglongitudinally of the work would prohibit placement of base 35 upon thework surface, and would make it impossible to bring the other feet intocontact with the parallel edges. The same limitation frequentlyrestricts the utility of known rigid foot devices in conjunction with awork surface of regular polygonal cross-section in which the polygon hasa number of sides which is not a multiple of four.

Thus, the center of an object of hexagonal cross-section, such as object110 in FIGURE 10, could not be determined with a rigid foot device byplacing two feet thereof in contact with opposite parallel sides, sincethe remaining two feetinstead of the base of the hub of the devicewouldrest upon the surface of the work and prohibit such placement. Rather,it would be necessary to resort to the obviously undesirable expedientof attempting to balance two feet upon the points of the work. so thatthe remaining feet would extend beyond the periphery thereof. With theinstant device, however, the center of work 110 can be quickly andaccurately located, and various desired upon arms 18, 20 into inactiveposition, placing base 35- of device 12 upon the work surface, bringingfeet 94 upon arms 22, 24 into contact with opposite parallel edges andlocking the arms in place, and sliding device 12 across the work untilopposite points of the hexagonal shape lie directly beneath bores andindicia 103 indicates that blocks 96 are equidistant from punch 82. Whenthe device is thus situated, as shown in FIGURE 10, the center of workand various radii therefrom can then be marked by means of punch 82 andblocks 96, as discussed heretofore.

Similar advantages of the instant device exist with respect to locatingthe center of a decagonal shape, to directly incribing the minor axis ofan elliptical shape, and in various other usages which will be apparentto those skilled in the art.

In the drawings and specification there has been set forth a preferredembodiment of the invention and, although specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation, the scope of the invention being defined in theclaims.

That which is claimed is:

l. A center locating device comprising a hub having a base adapted to bepositioned upon a work surface and a bore adapted to receive centermarking means intersecting said base, said hub having a plurality ofchannels extending therethrough about said bore generally parallel tothe plane of said base, elongated arm members slidably mounted withinsaid channels and extending beyond the ends thereof outwardly from saidhub, means on said hub interconnecting said arm members for simultaneousmovement through said channels, foot members carried by said armmembers, said foot members normally extending from said arm membersbelow the plane of said base of said hub and defining for any givenposition of said arm members relative to said hub the circumstance of animaginary circle having its center in alignment with the axis of saidbore of said hub, said foot members being movably mounted by said armmembers for free movement relative thereto through the plane of saidbase of said hub whereby said foot members are alternativelypositionable so as to be disposed when desired entirely above the planeof said base, stop means on said arm members intersecting the paths offree movement of said foot members and defining said first mentionedlocations thereof below the plane of said base, and radial-pointlocating members slidably mounted upon said arm members for movementtherealong between said foot members and said hub, said locating membersbeing disposed entirely above the plane of said base.

2. A center locating device comprising a hub having a base adapted to bepositioned upon a work surface and a bore intersecting said base adaptedto receive center marking means, said hub having two pairs of channelsextending therethrough parallel to the plane of said base, the channelsof each of said pairs extending on opposite sides of said bore parallelto each other and normal to the channels of the other of said pairs,elongated arm members slidably mounted in said channels and extendingbeyond the ends thereof, means on said hub interconnecting said armmembers for simultaneous coextensive movement through said channels withthe arms of each of said pairs moving in opposite directions to eachother, foot members pivotally mounted upon opposite ends of said armmembers of each pair of parallel arm members, the paths of pivotalmovement of said foot members intersecting the plane of said base ofsaid hub whereby said foot members are positionable in first locationsextending below the plane of said base and alternatively in secondlocations disposed entirely above the plane of said base, stop meansupon said arms intersecting the paths of pivotal movement of said footmembers and defining said first locations thereof below the plane ofsaid base, and radialpoint locating members slidably mounted upon saidarm members for movement therealong between said hub and said footmembers, said locating members being disposed entirely above the planeof said base.

3. A device as in claim 2, wherein there are openings communicating saidchannels and the surface of said hub opposite said base, and furtherincluding pin members slidably mounted within said openings with thelower ends thereof in engagement with said arm members within saidchannels and the upper ends thereof projecting above said surface ofsaid hub, and means on said hub for exerting simultaneous downwardforces upon the upper ends of said pins to urge said pins into lockingengagement with said arm members and thereby lock said arm membersagainst movement through said channels when desired.

4. A center locating device comprising av hub having a horizontal baseadapted to be positioned upon a work surface and a centrally locatedvertical bore intersecting said base, said hub having tWo pairs ofchannels extending therethrough parallel to the plane of said baseequidistant from said bore, the channels of each of said pairs extendingparallel to each other on opposite sides of said bore and normal to thechannels of the other of said pairs, elongated arm members slidablymounted within said channels and extending beyond the ends thereofoutwardly from said hub, means on said hub for moving said arm memberssimultaneously and coextensively relative to said hub through saidchannels, said means including an operating knob having an axial boreand a hollow interior portion communicating with said axial bore, saidknob being rotatively mounted upon said hub with said axial bore inalignment with said central bore of said hub, a center punch extendingthrough said central bore of said hub and said axial bore of said knoband having an annular notch intermediate its length, a leaf springmounted within said hollow portion of said knob and engaging said notchof said punch, said spring mounting said punch for reciprocatorymovement through said bores and resiliently maintaining said punch in anormally up--- ward position with one end of said punch projecting abovesaid knob and the other end of said punch housed within said bore ofsaid hub, bracket members mounted upon opposite ends of said arm membersof each pair of parallel arm members, pivot pins on said bracketsextending horizontally above the plane of said base of said hub, footmembers of generally L-shaped configuration mounted upon said pins forfree pivotal movement relative to said arm members in vertical pathsintersecting the plane of said base, first pin-stops extending from saidbrackets into the paths of pivotal movement of said foot members anddefining first locations thereof wherein the major legs of said L-shapedfoot members are disposed below the plane of said base of said hub andextend radially inwardly to- Ward the axis of said central bore of saidhub, second pin-stops on said brackets extending into the paths ofpivotal movement of said foot members and defining second locationsthereof wherein said foot members are disposed entirely above said planeof said base of said hub with said major legs of said foot membersextending radially outwardly from the axis of said central bore of' saidhub, radial-point locating members slidably mounted upon said armmembers for movement therealong between.

said bracket members and said hub, said locating members being disposedentirely above the plane of said base of' said hub and having verticalbores extending normal to imaginary radii of said central bore of said,hub, and means carried by said locating members for locking the sameagainst movement in desired positions along said arm members.

References Cited in the file of this patent

